1. Field of the Invention
The present invention relates to a device for a tool and, more particularly, to a rotation control device for a tool.
2. Description of the Prior Art
Referring to FIGS. 1-2, a conventional rotational prying tool 10 comprises a handle 11, a rotating block 12 and a prying head 13. The rotating block 12 is disposed in the handle 11, and the prying head 13 is mounted on both the handle 11 and the rotating block 12. The prying head 13 is provided with an engaging portion 131 on an inner surface thereof; while the rotating block 12 is provided with a engaging portion 121 on an outer surface thereof. The engaging portion 131 can be engaged with the engaging portion 121. Between one side of the rotating block 12 and the prying head 13 is disposed a spring 14, and the other side of the rotating block 12 is sealed with a seal cover 15. When the engaging portion 121 of the rotating block 12 is engaged with the engaging portion 131 of the prying head 13, the prying head 13 of the tool 10 can be used to perform the prying operation. When the seal cover 15 presses against the rotating block 12, causing compression of the spring 14, the engaging portion 121 of the rotating block 12 will be disengaged from the engaging portion 131 of the prying head 13, causing idle rotation between the rotating block 12 and the prying head 13. At this moment, the angle of the prying head 13 can be adjusted. However, as the rotating block 12 engages with the prying head 13 while being elastically pressed by the spring 14, it is not easy for the engaging portion 121 of the rotating block 12 and the engaging portion 131 of the prying head 13 to engage with each other in a very exact and precise manner, which will cause inconvenience in use, or even stuck fault. In addition, the single-flank engagement cannot provide enough engaging force, consequently reducing the output torque.
Moreover, U.S. Pat. No. 7,520,199 B2 discloses an “indexable pry tool and splined coupling arrangement therefore”. This pry tool is too complicated in structure, since it has many types of components. Especially, the first serrated insert and the second serrated insert are two different sized components, which require different manufacturing procedures and, therefore, will increase manufacturing cost. In addition, when assembling, the first and second serrated inserts should be assembled in a strict order in such a manner that the first serrated insert after assembly must be located between the second serrated insert and the circular planar head of the hold push button. Otherwise, no angle adjustment can be made between the indexable body and the handle, causing inconvenience in assembly.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.